When collecting data using Symdiag the concern arises regarding the capture of data like login credentials, key strokes or any other potentially sensitive data.
SymDiag does not collect any data such as described.
It only captures WSSA internal application trace logs which have no visibility into passwords, and the network and tunnel pcaps which has no visibility into the traffic flowing with TLS connections.
In an example scenario where someone visits a site that sends the credentials over a plain-text (HTTP - not HTTPS) request, then those would be visible in the pcap - but that would be a misconfigured site as credentials should never be passed in-the-clear.
WSSA does not have visibility into keystrokes or any traffic within a TLS connection.